<!DOCTYPE html>
<html>
<head>
  <style>
div { width:50px; height:30px; margin:5px; float:left;
      background:green; }
</style>
  <script src="http://code.jquery.com/jquery-latest.js"></script>
</head>
<body>
  <p><input type="button" value="Run"/></p>
<div></div>
<script>
jQuery.fx.interval = 1;
 
$("input").click(function(){
  $("div").toggle( 3000 );
});
  </script>
 
</body>
</html>